Question

The process of DNA transcription:

produces single stranded RNA complementary to the coding strand.

requires RNA polymerase.

is discontinuous.

produces double stranded DNA.

requires DNA polymerase III.

Among the significant sites that many eukaryotic promoters contain is:

a TATAAT box near –10.

a TATA site near –30 to –100.

a CATA site at the transcription start site.

a Pribnow box.

the Shine-Dalgarno sequence.

Answer 1

DNA transcription is a process of synthesising mRNA from the coding strand of dsDNA. So, choosing the correct options- produces single stranded RNA complementary to the coding strand, requires RNA polymerase. This is because mRNA synthesised will be complementary to coding strand as it is the only strand which is used to synthesise mRNA whose direction is 5' to 3' and for coding strand it is 3' to 5'. For synthesizing mRNA RNA polymerase is required not any type of DNA polymerase and the coding strand gives continuous strand of the product (DNA or RNA) as its direction is 3' to 5'.

Promoter is the term used for all the sequences important for initiation of transcription. Here, a TATA site near –30 to –100 is the sequence found in eukaryotes called TATA box while TATAAT box near –10, Pribnow box and the Shine-Dalgarno sequence is found in prokaryotes. Pribnow is an alternative name for TATA box but is used in prokaryotes and the Shine-Dalgarno is the sequence found on mRNA which is ribosomal binding site.